Summary. -All experimental data on the cluster decay probabilities of atomic nuclei obtained up to date are presented.
-IntroductionThe dependence of nuclear binding energy on the mass number makes possible a twobody decay of nuclei heavier than lead with formation of any particles, from an alphaparticle and up to fission fragments. Nuclei are kept in the bound state by the potential barrier. As the first approximation, the height of this barrier V C can be assumed to be equal to the Coulomb energy of the two touching spherical nuclei where Z 1 and Z 2 are the atomic numbers of the decay products; e is the electron charge;A 1 and A 2 are mass numbers; r 0 is the radius parameter. The energy deficit E relative to the barrier top is determined as follows: E = V C , Q, where Q is the difference between the masses of the initial and two final nuclei. Figure 1 presents the value of the energy deficit, E, for 232 U as a function of the atomic number Z 1 of the lighter decay product. Due to the choice of A 1 -values, we have used the highest possible Qvalues at a given value of Z 1 . The value of r 0 was accepted equal to 1.44 fm. We only show